TITLE: GCN CIRCULAR NUMBER: 40445 SUBJECT: EP250511a: FTW optical and NIR observations DATE: 25/05/12 17:53:13 GMT FROM: Malte Busmann at Ludwig-Maximilians-Universität München m.busmann@physik.lmu.de
Malte Busmann (LMU), Brendan O’Connor (Carnegie Mellon U.), Daniel Gruen (LMU), and Antonella Palmese (Carnegie Mellon U.) report:
We observed the localization of EP250511a (Lian et al., GCN 40429; Li et al., GCN 40434) with the Three Channel Imager (3KK) at the Fraunhofer Telescope at Wendelstein Observatory (FTW) in the r, i and J band simultaneously for 10 x 180 s starting at 2025-05-11T21:30:13 UT (0.56 days after the trigger). We do not detect the counterpart (Schneider et al., GCN 40431; Li et al., GCN 40433) placing 3 sigma upper limits at
r > 22.4 mag i > 22.0 mag J > 21.8 mag.
These upper limits are consistent with the mentioned detections and previous upper limits (Perez-Garcia et al., GCN 40430; Lipunov et al., GCN 40432; Brivio et al., GCN 40435; Zhong et al., GCN 40442).
The r and i band magnitudes are calibrated against the PS1 catalog and the J band is calibrated with the 2MASS Catalog. All magnitudes are provided in the AB system and are not corrected for Galactic extinction.
We thank Michael Schmidt from the Wendelstein Observatory staff for obtaining these observations.
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